A 5' to 3' exonuclease functionally interacts with calf DNA polymerase epsilon.
نویسندگان
چکیده
Analysis of fractions containing purified DNA polymerase epsilon from calf thymus has revealed the presence of a 5' to 3' exonuclease activity that is specific for a single strand of duplex DNA. This activity is capable of degrading a 3'-labeled oligonucleotide hybridized to M13mp18 DNA. When a second oligonucleotide primer is annealed 3 bases upstream, degradation of the downstream primer is strictly dependent on DNA synthesis from the upstream primer. Replacement of the downstream primer by an oligoribonucleotide of identical sequence results in a similar pattern of exonucleolytic activity. The activity has been highly purified and found to cosediment in glycerol gradients with a peptide of 56 kDa as judged by SDS/PAGE analysis. Effects of calf DNA polymerase alpha and delta on exonuclease activity are also observed but with differences in the pattern of products.
منابع مشابه
Proofreading by DNA polymerase III of Escherichia coli depends on cooperative interaction of the polymerase and exonuclease subunits.
The polymerase subunit (alpha) of Escherichia coli DNA polymerase III holoenzyme and the 3'----5' exonuclease subunit (epsilon) are each less active separately than together in the holoenzyme core (an assembly of alpha, epsilon, and theta subunits). In a complex formed from purified alpha and epsilon subunits, polymerase activity increased 2-fold, and that of the 3'----5' exonuclease increased ...
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عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 89 20 شماره
صفحات -
تاریخ انتشار 1992